Cracking and Decohesion Behavior of Electrogalvanized Coatings

The mechanical development of crack and decohesion in the various electrogalvanized coatings during deformation was analyzed by shear lag method. The original shear lag method was modified to allow the plasticity of steel substrate. This modified shear lag method enabled us to calculate not only stress distribution both in the coating and substrate, but also two fundamental fracture properties, viz., tensile strength of the coating and interfacial shear strength from the observed kinetics of microcrack formation. These fundamental properties were measured to compare the calculated values by the modified shear lag method with the experimental values directly obtained from the same coating.